U.S. patent number 6,425,690 [Application Number 09/670,144] was granted by the patent office on 2002-07-30 for positive lock for bearing subassembly and adjusting nut kit.
This patent grant is currently assigned to Reliance Electric Technologies, LLC. Invention is credited to Ryan N. DeWachter.
United States Patent |
6,425,690 |
DeWachter |
July 30, 2002 |
Positive lock for bearing subassembly and adjusting nut kit
Abstract
A bearing subassembly includes an improved arrangement for
securing the bearing subassembly to a shaft. An adjusting nut is
axially locked to a bearing inner ring by sliding the adjusting nut
over the inner ring so that a groove in the adjusting nut and
recesses, for example, pockets, on the inner ring align. Securement
elements, for example, balls, are inserted into the groove and
seated in the recesses through a bore from the outer diameter of
the adjusting nut to the groove. The inner ring is rotated to allow
the securement elements to fall into the recesses and are enclosed
between the groove and recesses by inserting, for example, a set
screw after the securement elements are loaded. The securement
arrangement then prevents the bearing subassembly adjusting nut and
inner ring from separating.
Inventors: |
DeWachter; Ryan N.
(Simpsonville, SC) |
Assignee: |
Reliance Electric Technologies,
LLC (Mayfield Heights, OH)
|
Family
ID: |
24689173 |
Appl.
No.: |
09/670,144 |
Filed: |
September 26, 2000 |
Current U.S.
Class: |
384/583; 384/538;
384/540; 384/585 |
Current CPC
Class: |
F16C
33/586 (20130101); F16C 35/073 (20130101); F16C
2226/16 (20130101); F16C 23/086 (20130101); F16C
19/38 (20130101) |
Current International
Class: |
F16C
35/063 (20060101); F16C 35/04 (20060101); F16C
025/06 () |
Field of
Search: |
;384/519,540,585,537,538,583 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Footland; Lenard A.
Attorney, Agent or Firm: Klosowski, Jr.; Bernard S.
Gerasimow; Alexander M. Walbrun; William R.
Claims
I claim:
1. A bearing subassembly for rotatably supporting a shaft within a
shaft mounting assembly, the bearing subassembly comprising: a
bearing inner ring member defining an axial opening, the bearing
inner ring member having an outer surface including a
circumferential portion defining at least one recess therein; an
adapter extending around the shaft and disposed within the axial
opening; an annular adjusting nut configured to slidably and
concentrically receive the bearing inner ring member and to be
secured to the adapter, the adjusting nut defining an internal
surface and an inner groove disposed circumferentially about the
adjusting nut internal surface, the adjusting nut further defining
an external surface and abore extending between the adjusting nut
external surface and the adjusting nut inner groove; and at least
one securement member insertable through the bore and disposed
between the adjusting nut inner groove and the bearing inner ring
member at least one recess to thereby axially secure the bearing
inner ring member to the adjusting nut.
2. The bearing subassembly as in claim 1, wherein the bearing inner
ring member defines an outer circumferential raceway in
communication with the shaft mounting assembly.
3. The bearing subassembly as in claim 1, wherein the at least one
securement member is a ball.
4. The bearing subassembly as in claim 3, wherein the at least one
recess is generally bowl-shaped.
5. The bearing subassembly as in claim 1, wherein the at least one
recess is a groove disposed circumferentially about the bearing
inner ring member outer surface.
6. The bearing subassembly as in claim 5, wherein the at least one
securement member is a ball.
7. The bearing subassembly as in claim 1, further comprising a set
screw removably disposed within the bore.
8. An adjusting nut kit for securing a rotatable shaft to a bearing
inner ring member of a shaft mounting assembly via an adapter
disposed about the shaft, the bearing inner ring member having an
outer surface including a circumferential portion defining at least
one recess therein, the adjusting nut kit comprising: an annular
adjusting nut having an internal surface defining an inner
circumferential groove, the adjusting nut also defining a bore in
communication with the groove, the groove in the adjusting nut
opposing the at least one recess in the bearing inner ring member
when the adjusting nut is secured to the adapter; and at least one
ball insertable through the bore into the at least one recess and
the groove to axially secure the adjusting nut to the bearing inner
ring member.
9. The adjusting nut kit as in claim 8, further including a set
screw removably insertable into the bore.
10. The adjusting nut kit as in claim 8, wherein the kit includes
the adapter, and wherein the adjusting nut and the adapter are
securable together via mating threads.
11. The adjusting nut kit as in claim 8, wherein the at least one
recess is generally bowl-shaped.
12. The adjusting nut kit as in claim 8, wherein the at least one
recess is a groove disposed circumferentially about the bearing
inner ring member outer surface.
13. A bearing subassembly for rotatably supporting a shaft within a
shaft mounting assembly, the bearing subassembly comprising: a
bearing inner ring member having an outer surface including a
circumferential portion defining at least one recess therein; an
annular adjusting nut configured for securement to the bearing
inner ring member, the adjusting nut defining an internal surface
and an inner groove disposed circumferentially about the adjusting
nut internal surface, the adjusting nut further defining an
external surface and a bore extending between the adjusting nut
external surface and the adjusting nut inner groove; and at least
one securement member insertable through the bore and disposed
between the adjusting nut inner groove and the at least one recess
to thereby axially secure the bearing inner ring member to the
adjusting nut.
14. The bearing subassembly as in claim 13, further comprising
means for removably sealing the bore to hold the at least one
securement member between the adjusting nut inner groove and the at
least one recess.
15. The bearing subassembly as in claim 13, wherein the at least
one recess comprises a plurality of generally bowl-shaped
recesses.
16. The bearing subassembly as in claim 13, wherein the at least
one recess comprises a continuous circumferential groove disposed
about the bearing inner ring outer surface in communication with
the groove of the adjusting nut.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a shaft mounting
assembly. More particularly, the invention relates to a multi-piece
bearing subassembly securable as a single unit to a shaft within a
shaft mounting assembly.
Shaft mounting assemblies are often designed to be quickly attached
to a shaft. Typically, a bearing subassembly is first slipped along
the shaft to the desired position. Once there, the inner ring of
the bearing subassembly is secured to the shaft utilizing one of
various clamping techniques, such as use of a tapered adapter
having a tapered outer surface and an axial bore for receipt of the
shaft. The tapered adapter is forced axially into a tapered opening
in the inner ring by manipulation of an adjusting nut. The tapered
adapter is closed around the shaft by mating threads on one end of
the adapter and corresponding threads on the adjusting nut. Further
sliding of the bearing inner ring along the tapered outer surface
achieves a press fit between the tapered surfaces.
Generally, bearing subassemblies utilizing tapered adapters have
been commercially available in two types, a pull type and a push
type. One pull-type adapter is illustrated in U.S. Pat. No.
5,011,306 issued Apr. 30, 1991 to Martinie. In the pull type,
threads are defined on the tapered adapter adjacent its lesser
diameter end, and an adjusting lock nut is tightened onto the
threads to pull the tapered adapter into the shaft bore of the
bearing subassembly. A number of push-type adapter designs are
shown in U.S. Pat. No. 5,685,650 issued Nov. 11, 1997 to Martinie
et al. In a push-type adapter, threads are disposed on the greater
diameter end of the adapter, and the adapter is pushed into the
bearing inner ring by rotation of the adjusting nut relative to the
adapter. In one of the push-type designs, a radially-compressible
snap ring provides an annular interconnection between the adjusting
nut and bearing inner ring. The snap ring is placed in a groove on
an outer surface of the bearing inner ring and the nut is axially
moved onto the bearing inner ring such that the nut leading surface
compresses the snap ring into the groove. When an opposed groove in
an inner surface of the nut is aligned with the groove in the
bearing inner ring, the snap ring expands into the nut groove to
connect the nut and inner ring member.
A limitation of this design is the occasional inability to
ascertain whether the snap ring is seated properly due to burrs or
other anomalies on the snap ring. Further, even if a snap ring is
seated properly, large load forces could, on rare occasions, cause
a defective snap ring to break or prematurely unseat. Improperly
seated, broken, or unseated rings could lead to separation of the
bearing assembly, potentially resulting in equipment damage and
costs associated with servicing affected equipment.
OBJECTIVE AND SUMMARY OF THE INVENTION
It is accordingly an objective of the present invention to provide
a bearing subassembly having a positive locking arrangement between
the inner ring and adjusting nut.
It is another objective of the present invention to provide an
improved shaft mounting assembly for securing a bearing to an
elongated shaft.
It is yet another objective of the invention to provide a simple,
economical, and reliable locking arrangement and clamping
assembly.
Some of these objects are achieved by a bearing subassembly
according to the present invention. The bearing subassembly
includes a bearing inner ring with an axial opening. The bearing
inner ring has an outer surface which includes a circumferential
portion having at least one recess. An adapter extends around the
shaft and within the axial opening of the bearing inner ring. An
annular adjusting nut is configured to receive the bearing inner
ring and to be secured to the adapter. The adjusting nut defines an
internal surface and an inner groove disposed circumferentially
about the adjusting nut internal surface. The adjusting nut further
defines an external surface and a bore extending between the
adjusting nut external surface and the adjusting nut inner groove.
Securement members are insertable through the bore and disposed
between the adjusting nut inner groove and the bearing inner ring
recess to axially secure the bearing inner ring member to the
adjusting nut. In this construction, the inner ring recesses may be
bowl shaped pockets.
In another exemplary construction, an adjusting nut kit for
securing a rotatable shaft to a bearing inner ring having a
plurality of recesses on its outer surface to a shaft mounting
assembly includes an annular adjusting nut having an internal
surface defining an inner circumferential groove. The adjusting nut
further defines a bore in communication with the groove. The groove
in the adjusting nut opposes the recesses in the bearing inner ring
member when the adjusting nut is secured to the adapter. Balls are
insertable through the bore into the recesses and the groove to
axially secure the adjusting nut to the bearing inner ring member.
A set screw, for example, can be used to close the radial bore.
Another aspect of the invention includes a method of securing a
bearing subassembly to a shaft. The method comprises sliding an
inner ring with recesses disposed circumferentially on one end of
the ring onto the shaft. Next, a tapered adapter is slid onto the
shaft proximate the inner ring. An adjusting nut with a
circumferential groove disposed internally about one end is then
slid onto the shaft via the nut's bore. The adjusting nut is mated
to one end of the inner ring. The other end of the adjusting nut is
mated to one end of the adapter. The adjusting nut is rotated until
the bore aligns with one of the recesses so that they oppose the
opposite groove. A ball bearing is inserted through the bore into
the recess. The adjusting nut is rotated repeatedly and balls are
inserted until the recesses are filled. The bore is closed and the
adjusting nut is rotated to axially press fit the adapter to the
shaft.
Other objectives, features, and aspects of the present invention
are discussed in greater detail below or may be learned through
practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including
the best mode of carrying out the invention, to one of ordinary
skill in the pertinent art is set forth more particularly in the
remainder of the specification including reference to the
accompanying drawings in which:
FIG. 1 is a partial, cross-sectional view of an exemplary
embodiment of a shaft mounting assembly and bearing subassembly
disposed around a shaft and constructed in accordance with the
present invention;
FIG. 2 is an enlarged, partial, cross-sectional view of a portion
of the device of FIG. 1;
FIG. 3 is an exploded view of the bearing subassembly as removed
from the shaft;
FIG. 4A is a partial sectional view showing a method of inserting
securement elements into a bearing inner ring of the bearing
subassembly;
FIG. 4B is a further view of the method as shown in FIG. 4A showing
one securement element inserted and the bearing inner ring
positioned for receiving a second securement element;
FIG. 5A is a partial sectional view showing an alternative bearing
inner ring design having a groove to hold the securement elements
in contrast to the singular recesses shown in FIG. 4A; and
FIG. 5B is a partial sectional view as in FIG. 5A showing a number
of securement elements in place within the groove.
Repeat use of reference characters in the present specification and
drawings is intended to represent same or analogous features or
elements of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is to be understood by one of ordinary skill in the pertinent
art that the following description of exemplary embodiments is not
intended as limiting the broader aspects of the present invention,
which is defined by the scope of the appended claims and their
equivalents.
Referring now to FIG. 1, a shaft mounting assembly 10 constructed
in accordance with a preferred embodiment of the present invention
is shown secured to a shaft 12. FIG. 1 also reveals a tapered
adapter 14 through which shaft 12 extends and a bearing inner ring
member 16 is received about tapered adapter 14. Ring member 16
includes at least one raceway 16a for receiving a plurality of
bearings B. As described herein, shaft mounting assembly 10
includes bearing inner ring member 16 of bearing assembly 17. It
should be understood that bearing assembly 17 could be any type of
assembly suitable for supporting a rotatable shaft. Thus, further
details of bearing assembly 17 need not be given to enable one
skilled in the art to appreciate and practice the claimed
invention.
FIG. 2 particularly shows a bearing subassembly 18 cross-section
enlarged from FIG. 1. The bearing subassembly 18 includes the
tapered adapter 14, the inner ring 16, an adjusting nut 20, and a
securement element 22. Although bearing inner ring member 16 is
typically commercially supplied as part of bearing assembly 17, it
should be understood that the bearing subassembly 18 described
below includes such bearing inner ring 16.
Tapered adapter 14 further defines a tapered outer surface 24
extending between a first end 26 of lesser diameter and a second
end 28 of greater diameter. As shown in FIG. 2, inner ring member
16 defines a tapered inner surface 30 generally complementary to
tapered outer surface 24 and having larger and smaller diameter
ends 34 and 32. Adapter 14 further defines a radial slot 36
extending along its entire axial length as can be most easily seen
in FIG. 3. Radial slot 36 allows the adapter 14 to contract around
the shaft 12 as tapered outer surface 24 and tapered inner surface
30 are moved axially together. As a result, positive clamping of
bearing subassembly 18 to shaft 12 is achieved. Tapered adapter 14
further includes an extension portion 38 axially extending from the
larger diameter end 28 of tapered outer surface 24. Similarly,
inner ring 16 includes an extension portion 40 axially extending
from a larger diameter end 42 of tapered inner surface 30.
The nut 20 includes a first axial portion 44 defining inner threads
46 for engaging outer threads 48 defined about the extension
portion 38. As will be described more fully below, nut 20 is
connected to inner ring 16 via extension portion 38 such that axial
movement of nut 20 will cause corresponding axial movement of inner
ring 16. However, threads 46 and 48 connect nut 20 to extension
portion 38 so as to also allow free rotation of nut 20 about
extension portion 38 and correspondingly slight relative axial
movement. Thus, once nut 20 is secured to bearing inner ring 16,
rotation in one direction of nut 20 will push adapter 14 into
bearing inner ring 16 to cause tapered outer surface 24 and tapered
inner surface 30 to be moved into engagement. Rotation of nut 20 in
the opposite direction will pull adapter 14 out of bearing inner
ring 16 to cause tapered outer surface 24 and tapered inner surface
30 to be moved out of engagement.
Referring now particularly to FIG. 3, a preferred manner by which
nut 20 may be suitably connected to inner ring 16 is illustrated.
As shown, a plurality of pockets 50 are defined about the outer
surface 52 of the inner ring extension portion 40. A
circumferential groove 54 is defined about an inner surface 56 of a
second axial portion 58 of nut 20. The groove 54 preferably has a
substantially semicircular cross-section and pockets 50 preferably
are substantially hemispherical (i.e., bowl shaped). In use,
pockets 50 and groove 54 are radially opposed.
In accordance with the invention, securement members 22 are
provided to axially secure together inner ring member 16 and nut
20. As illustrated, such securement members 22 preferably comprise
a plurality of substantially spherical members such as balls. As
shown best in FIG. 2, pockets 50 and groove 54 are of sufficient
radius and depth to permit members 22 to be received entirely
therein. Members 22 are disposed substantially equally between
pockets 50 and groove 54 to cause nut 20 to be axially locked to
inner ring 16.
Referring again to FIG. 3, nut 20 further defines an opening 60 in
communication with groove 54 through which members 22 may be
inserted. As shown, the opening 60 preferably extends radially, but
the opening 60 could extend axially or in some other direction or
combination of directions if desired. Also, opening 60 is
preferably threaded for receiving a set screw 62, although other
devices that snap, slide, or plug in could be utilized instead.
Removal of the set screw 62 permits members 22 to be placed through
opening 60 into the groove 54. If opening 60 is not aligned with a
pocket 50 when a member 22 is inserted, rotating nut 20 relative to
inner ring 16 will bring a pocket 50 into alignment with the
opening 60 allowing the member 22 to enter the pocket 50. Further
relative rotation causes the pocket 50, into which the member 22
has entered, to carry the member 22 along with it. Upon further
relative rotation, an adjacent pocket 50 will align with the
opening 60 allowing another member 22 to enter the adjacent pocket
50. This process is continued until all pockets 50 contain members
22 at which point the inner ring 16 is axially but not rotatably
locked to nut 20. Set screw 62 may be replaced to prevent members
22 from falling out of groove 54 and pockets 50. Opposite rotation
of nut 20 and inner ring 16 drives tapered adapter 14 axially into
the inner ring 16 due to interaction of threads 46 and 48. Such
axial movement eventually rotationally locks inner ring 16 and
tapered adapter 14 due to frictional engagement of tapered surfaces
24 and 30.
As described herein, nut 20 and securement members 22 may be
considered to comprise an adjusting nut kit that could be
separately sold for use with various bearing assemblies, such as
assembly 17. The kit could also include tapered adapter 14, if
desired, as well as set screw 62.
FIGS. 4A and 4B illustrate a method of positively locking bearing
subassembly 18. As shown, members 22 are inserted sequentially into
pockets 50. FIG. 4A illustrates inserting a first member 22 into a
first pocket 50 and FIG. 4B illustrates further methodically
relatively rotating adjusting nut 20 to align the opening 60 with
an adjacent pocket 50 for receipt of a second member 22. To
disassemble bearing subassembly 18, the opposite steps are
taken.
FIG. 5A illustrates an alternative inner ring 116. In this case,
pockets 50 are replaced by an external groove 150 for receipt of
securement members 122. External groove 150 extends
circumferentially around inner ring 116 and is substantially
semicircular in cross-section. A greater number of members 122 are
preferably provided so as to substantially fill inner ring groove
150. The method of inserting members 122 is essentially the same as
above. FIG. 5B illustrates methodically rotating adjusting nut 120
to align the set screw opening 160 above an opening of groove 150
for sequential receipt of a plurality of members 122.
While preferred embodiments of the invention have been shown and
described, modifications and variations may be practiced by those
of ordinary skill in the art without departing from the spirit and
scope of the present invention which is more particularly set forth
in the appended claims. For example, the securement members need
not be spherical (balls). Other types of securement members, such
as cylindrical rollers, could also be employed. Also, the location
and path of the opening for inserting the securement members could
be altered from that shown in several ways by reconfiguring the
adjusting nut or bearing inner ring. In addition, it should be
understood that aspects of the various embodiments may be
interchanged both in whole or in part. Those of ordinary skill in
the art will appreciate that the foregoing descriptions are by way
of example only and are not intended to limit the invention so
further described in the appended claims.
* * * * *